Occurrence of Free-Form and Conjugated Bisphenol Analogues in Marine Organisms

Upon exposure, most bisphenol analogues (BPs) are rapidly metabolized to BP conjugates in organisms. Monitoring studies on BPs in aquatic organisms have been mainly focused on free-form BPs. However, the relative amount of conjugated BPs in organisms is still not well known, especially in marine organisms. In this study, we collected marine organisms (13 species; n = 74), as well as seawater (n = 15), from East China Sea, and analyzed them for bisphenol A (BPA) and its eight analogues. In seawater, BPA was the predominant BP (mean ± standard deviation (SD), 18 ± 9.7 ng/L), followed by bisphenol S (BPS; 3.7 ± 2.8 ng/L), bisphenol F (BPF; 0.31 ± 0.17 ng/L), and bisphenol AF (BPAF; 0.24 ± 0.15 ng/L). The whole body of each marine organism was used for BP analysis in this study. BPA (mean 3.8 ng/g, range 1.2-7.7 ng/g) and BPS (1.5 ng/g, 0.19-6.1 ng/g) were still the predominant BPs in marine organisms without hydrolysis. After enzymatic hydrolysis treatment, mean concentrations of BPs increased 1.8 (BPS)-3.7 (BPA) times in marine organisms. Correspondingly, on average, 74, 52, 49, 48, and 45% of BPA, bisphenol Z, BPF, BPS, and BPAF were present in conjugated forms, respectively, in marine organisms. Moreover, bioaccumulation and biomagnification of BPs were evaluated using pooled marine organism samples. We first found that the mean log BAF values of BPs increased 0.091 (BPAF) to 0.31 (BPA) times in marine organisms after hydrolysis. Overall, this study first determines the amount of BPs present in conjugated forms in marine organisms, which are helpful for better understanding the occurrence of BPs in organisms.